A. Weissenborn in East German patent 11,191 (1956) describes a produce for the preparation of Jasmine aldehyde wherein the catalysts are Ni, Co or Fe salts of carboxylic acids. The reaction is carried out at the temperature range of 180-190.degree. C., in the presence of toluene in order to facilitate azeotropic distillation of the water and the heptanal is added slowly to the reaction mixture. Yields around 80% of Jasmine aldehyde are obtained.
R. Mahrwald and H. Schick in East German patent DD 287,712 (1991) describe a procedure wherein the aldolic condensation between heptanal and benzaldehyde is accomplished in the presence of Titanium compounds (tetraisopropiltitanium) and toluene as the azeotropic agent. Yields around 56% of Jasmine aldehyde are obtained.
L. S. Payne in European patent 392,579 (1990) describes a procedure for the selective preparation of .alpha.-cinnamaldehydes by aldolic condensation in two phases, using glycols (especially ethylene glycol) as solvents and sodium or potassium hydroxides as catalysts. Yields around 90% of .alpha.-cinnamaldehyde are obtained.
P. Mastagli et al. in Bull. Soc. Chim. France, 1955, p. 268, describe the preparation of Jasmine aldehyde using anionic exchange resins (IR-4B) as catalysts. The yields obtained varied between 2 and 12%.
The same author describes in Compt. Rend. 1957 vol. 244, p. 207, a process starting from n-alkyl aldehyde and benzaldehyde acetals using as a catalyst a mixture of an acid catalyst (cationic exchange resin) and a basic catalyst (anionic exchange resin) in order to produce the hydrolysis and aldolic condensation respectively. The yields obtained varied between 5 and 28%.
A. Sakar et al. in Ind. J. Chem., 1986, vol. 25,p. 656 accomplish aldolic condensation using potassium carbonate and a phase transfer catalyst such as benzyltriethylammonium chloride. On the other hand, D. Abenhaim et al in Synthetic Comm., 1994, vol. 24, p. 1199 carry out condensation using the same type of catalysts but under microwave effect. In both cases yields around 80% of Jasmine aldehyde are obtained.